International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 5- March 2015
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Embedded systems &
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Department of E I E & GITAM University, Visakhapatnam, Andhra Pradesh, INDIA
Abstract
—This paper deals with the implementation of portable voice-based authentication system by using Bluetooth with the help of android application. Existing methods are expensive and also speech recognition is available with different techniques but here we are using our own android app for speech recognition technology and Raspberry Pi for controlling Purpose. Human voice converted into text by using Android app and wirelessly transferred to Bluetooth module which is connected to
Raspberry Pi. According to text the corresponding application will works.
Keywords
Raspberry Pi, HC-05 Bluetooth module, Android App
I.
I NTRODUCTION
A.
RASPBERRY PI
The Raspberry Pi is a low cost, credit-card sized computer that plugs into a computer monitor or TV uses a standard keyboard and mouse. It is a capable little device that enables people of all ages to explore computing, and to learn how to program in languages like Scratch and Python. It’s capable of doing everything you’d expect a desktop computer to do, from browsing the internet and playing high-definition video, to making spreadsheets, word-processing, and playing games. Raspberry pi has ability to interact with outside world, and has been used in a wide array of digital maker projects, from music machines and parent detectors to weather stations and tweeting birdhouses with infra-red cameras. In this
Project we are using Raspberry Pi B board and those specs are as follows
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Memory : 512 Mb RAM
The most important element of this project is that we can run on a low cost embedded device such as a Raspberry pi, and for voice recognition better solution here we used is our own
Android app and the communication made possible by using
Bluetooth module. At first the Smartphone recognizes our voice with the help of Android app and converts into text, and the text transferred through Bluetooth of phone to external
HC-05 Bluetooth module which was connected to Raspberry pi board then the Bluetooth transfers the message to our target board serially with half duplex communication and the
Raspberry Pi searches the command given by us. If it found then the corresponding will works. For this work we have to implement the code by using python/Linux commands or
Embedded C. Based on the particular code our voice command works if it has the command. It is very helpful to implement a group of projects on single board and that to works on voice, main purpose of the project is to implement a small laboratory prototype of electronic projects to the students. Not only lab projects it might be helpful for automation applications.
II. SYSTEM OVERVIEW
The main elements of this project are that Raspberry Board,
Bluetooth module HC-05 and smart phone with android app.
Here Raspberry works for controlling purpose and Bluetooth is for communication unit. Android app is for receiving the input voice signals.
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Connections : 2 USB ports
Ethernet port(10/100
BaseT Ethernet socket
3.5mm jack for audio out
HDMI composite video
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Processo r: SoC is a Broadcom BCM2835 o This contains an ARM1176JZFS (ARM11 using an ARMv6-architecture core) with floating point, running at 700Mhz, and a
Video core 4 GPU.
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OS : Boots from SD card, running a version of the
Linux(Rasbian) operating
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Power : Micro USB socket 5V, 2A
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26 GPIO pins
As the operating system Raspbmc distribution was used ( http://www.raspbmc.com/ ) (aunque tests with Raspbian distribution were also made without any problem). In order to run the operating system, programs and storing multimedia content, an SD card 8 GB Class 10 Regarding the RAM used by each module was used, tests were conducted and it was determined that the media center used to 70 MB while a movie (http://www.bigbuckbunny.org/) format 1080p H.264 hardware decoding and reproduced, while the authentication system with all modules and arrays came to use up to 6 MB,
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International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 5- March 2015 and server using 1 MB. This confirmed that the 512 MB available were sufficient, so the final system memory was partitioned so that the GPU could use 256 MB and leave the rest to the CPU.
Fig 2 :HC-05 Bluetooth Module
Fig .1. Raspberry Pi B board
B.
BLUETOOTH MODULE
Bluetooth Smart technology is a wireless communications system intended to replace the cables connecting many types of devices, from mobile phones and headsets to hear monitors and medical equipment. In my project I am using another module for communication between voices from smart phone to raspberry pi by using Bluetooth module. For this purpose
HC-05 module being used and the specifications of Bluetooth module as follows.
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Bluetooth protocol: Bluetooth Specification v2.0+EDR
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Frequency:
Modulation:
Keying)
Sensitivity:
Speed:
2.4GHz ISM band
Asynchronous: 2.1Mbps(Max) / 160 kbps,
Synchronous: 1Mbps/1Mbps
Security:
Profiles:
GFSK(Gaussian Frequency Shift
Emission power : ≤4dBm, Class 2
≤-84dBm at 0.1% BER
Authentication and encryption
Bluetooth serial port
Power supply: +3.3VDC 50mA
Working temperature : -20 ~ +75Centigrade
Fig.3.Bluetooth Pin Out Diagram
We have to connect this Bluetooth module to Raspberry pi to control our requirements based on our input given by us through the app.Here Communication applied based on half duplex communication. And the key element in this project is voice so we have to discuss about the Android app for transmission of voice signals.
C.
ANDROID APPLICATION
Many apps are existed in Google play store but we can’t modify the background process so here we are using our own android application which is prepared using MIT app inventor
2. By using this we can modify background operation based on our requirements so corresponding person have complete idea about what are the inputs. So this is the major advantage of this project.
Steps to create Application:
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Go to www.google.com
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Search MIT app inventor2
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Click on MIT app inventor 2 Login with Gmail
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Take survey later
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Continue
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Create new project
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And we can build our app with help of options provided in left side.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 5- March 2015
III. PROJECT DESIGN METHODOLOGY
A. WIRELESS TRANSMISSION OF TEXT
In this project first and main thing is that converting voice signal to text that can be made possible by our own Android app i.e. as follows
Voice given to smart phone
Converted into text using app and transferred from mobile
Bluetoo th
HC-05
Bluetooth module
Fig .4. Wireless Transmission of Text
The Voice which was taken by ours can be converted into text
vcc
Rxd
Txd
Gnd
Vcc
Txd
Rxd
Gnd
Bluetooth HC-05 Raspberry Pi by using an android app designed in MIT app inventor2 and it
D.
will transferred from our mobile Bluetooth to HC-05 module which is connected to Raspberry pi Board. The text Here Raspberry Pi used for controlling purpose and it is transferred from Smartphone Bluetooth to Hc-05 Bluetooth serially in a half duplex manner .
B. CONNECTING FROM BLUETOOTH OF SMARTPHONE almost like a small computer so to start with this we have to configure the board. The programming language here going to use is python.
We are going to running a recent release of
Raspbian on my Raspberry Pi. Commands for required
The voice can be converted as text by using my app and installations as follows before converting into text we have pair with HC-05 and scan 1. sudo apt-get install python-dev for python installation for devices and connect to that Bluetooth then the LED
the 2. sudo apt-get install python-rpi-gpio for accessing GPIO
Bluetooth module blinks rapidly that is the sign that the module is ready and waiting for another device to pair up.
Then the devices are paired, if we give voice that can be pins of Raspberry pi
Both the commands can be done by in online manner we can done it in offline also. By default the Raspberry Pi is converted into text and transferred to HC-05 which is configured to write boot time messages to the serial port, and connected to Raspberry pi and searches the command whether also to start a login console on it. Unfortunately, the default it was written in the code or not, if result is positive then it baud rate that the RPi uses for its serial port is 115200 bps, works based on that particular command
C. BLUETOOTH INTERFACING
while the Bluetooth module comes preconfigured from factory to 9600 bps. It is easier to configure the RPi to use 9600 bps so we will try that first. There are two config files that need to
The voice signals from can be converted into text and transferred to HC-05 Bluetooth from Bluetooth in the smart be updated. phone. The HC-05 module connected to Raspberry pi as follows
File /boot/cmdline.txt contains the kernel options that are used to boot the system. In my Raspbian based system this file contains the following options:
Bluetooth module(HC-05) Raspberry pi GPIO
Vcc
Rxd
Txd
GND
Vcc(pin #2)
Txd(pin #10)
Rxd(pin #8)
GND(pin #6)
Pin connection from Bluetooth to Raspberry pi dwc_otg.lpm_enable=0console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
The interesting options are console and kgdboc, because these configure the serial port device
/dev/ttyAMA0 to 115200 bps.
We need to change these two configurations to 9600 bps.
After you make these changes the file should read
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International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 5- March 2015 dwc_otg.lpm_enable=0 console=ttyAMA0,9600 1. Button has ability to detect clicks. Many aspects of its kgdboc=ttyAMA0,9600 console=tty1 appearance can be changed as well as whether it is clickable, can be changed, as well as whether it is clickable can be root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline changed in the designer or in the blocks editor. rootwait 2. A label can display a piece of text, which is specified
The second configuration file is /etc/inittab. Inside this file you have to locate the following line:
T0:23:respawn:/sbin/getty
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L ttyAMA0 115200 vt100
This tells the system to start a terminal on the serial port, and again it uses 115200 bps to configure the port. You have to change this line to use 9600 bps:
T0:23:respawn:/sbin/getty ‐ L ttyAMA0 9600 vt100.
Remember that these are configuration files so they are not writable to the default pi user, to edit these files you have to use sudo. As far as text editors, Raspbian provides two, vi and pico. For example, to edit cmdline.txt with pico you would run the following command:
$ sudo pico /boot/cmdline.txt through the Text property. Other properties, all of which can be set in the Designer or blocks Editor, control the appearance and placement of text.
3. A button that, when clicked on, displays a list of texts for the user to choose among. The texts can be specified through the Designer or Blocks Editor by setting the Elements From
String property to their string-separated concatenation (for example, choice 1, choice 2, choice 3 ) or by setting the
Elements property to a List in the Blocks editor.
And for speech recognition we need speech recognizer which helps to converts the speech to text and Bluetooth client is also necessary for transmission and we have to pair up the
Bluetooth module with smart phone Bluetooth. The text from able to make changes to this file. I recommend that we save original copies of these config files in case we make a mistake.
E ANDROID APP MAKING
Here we used MIT app inventor2 to prepare own application based on our requirement .Steps to prepare an app as follows
1. Open the browser and open www.google.com
2. search for MIT app inventor2 and click on app inventor 2
3. Login with Gmail account
4. Take survey later
5. Create new project with project name transmission the properties are as follows
Addresses and Names
The addresses and names of paired Bluetooth devices
Available
Whether Bluetooth is available on the device
Character Encoding
DelimiterByte
Enabled
Whether Bluetooth is enabled
HighByteFirst
IsConnected
Secure whether to invoke SSP (Simple Secure Pairing), which is supported on devices with Bluetooth v2.1 or higher. When working with embedded Bluetooth devices, this property may need to be set to False. For Android 2.0-2.2, this property setting will be ignored. We need a clock i.e. Non-visible component that provides the instant in time using the internal clock on the phone. It can fire a timer at regularly set intervals and perform time calculations, manipulations, and conversions.
Methods to format the date and time are also available. All these elements are used in Designer section and the final designer for our application is as follows
Fig .5 New project window
Left side we have buttons, list pickers, labels and many predefined blocks for the purpose of different applications.
The application is for Bluetooth transmission so we need button, list picker and these blocks are available in user interface.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 5- March 2015
After the creation of app we have to save the project. And we have a build option at the top to create .apk file to install the app into our phone and the screen shot of this app is given below
Fig .6 APP Designer
To perform the operations with that button, label, list pickers,
Bluetooth client we need to write the code and that will be in blocks section .In this blocks section we have different inbuilt components with the help of that blocks we have to prepare the code.
What we mentioned in the above pages is all about what are elements we used and how it works and the final block diagram is
Fig .9 Block Diagram
The main program for this system written by using python.
Fig .7 Blocks window
With the help of blocks we can prepare code for corresponding application and for this paper the final code for
App is
IV. PROPOSED SYSTEM
Finally our proposed is consists of Smartphone with app,
Bluetooth module HC-05, Raspberry pi B board and target board.
Fig .8 parts of App code
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Fig .10 Prototype of proposed system
This is the basic arrangement to implement our idea it consists a smart phone acts as voice input and that can be send to
Bluetooth module which was connected to Raspberry pi and http://www.ijettjournal.org
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International Journal of Engineering Trends and Technology (IJETT) – Volume 21 Number 5- March 2015 searches the text what we written in the code section of
Raspberry pi .If the text matches then the corresponding
Similarly different sensors could be interface with the microcontroller by using analog to digital convertor or section will executes. comparator circuit. So any sensors can be connected with the remote station according to the system.
V. CONCLUSION AND FUTURE SCOPE
Implementation of portable voice-based authentication system using Bluetooth and our own Android app is very in expensive and it is very useful project for the adults and physically disabled persons, With the Voice Recognition along with
Bluetooth network we can eliminate the complication of wiring in case of wired automation and also it prevent to get up and down again and again to on/off appliances. It very in expensive it can be help in improves small laboratory works also.
Fig .11 small Arrangements of home appliances
In the power section a simple 9-12V battery is connected with the transmitting end as well as receiving end or we may use
12V adapter to drive AC elements. Since the microcontroller which is the central processing unit works on regulated +5V power supply so this can be achieved by connecting a +5 volt regulator at the output of battery. This is shown in figure 12.
R EFERENCES
1 . L. Rabiner, ―A tutorial on Hidden Markov Models and selected applications in speech recognition,‖ Proceedings of the IEEE , vol. 77, pp. 257–286, 1989.
2.www.imagesco.com/articles/hm2007/SpeechRecognitionTut orial01.html
3. V. Ramya, B. Palaniappan, Boby George, Embedded
System for Automatic Irrigation of Cardamom Field using
Xbee-PRO Technology, International Journal of Computer
Applications (0975 – 8887) Volume 53– No.14, September
2012 .
.
4. F. L. Alegre, "Application of ANN and HMM to Automatic
Speaker Verification", IEEE LATIN AMERICA
TRANSACTIONS, Vol. 5, No. 5, pp. 329-337, Sept. 2007
5. http://appinventor.mit.edu/explore/
Fig .12: Power supply unit
A single relay switch connection to microcontroller is shown below. Any home appliance operating under A.C voltage supply could be connected directly with this relay interface circuit. A buzzer can also be connected by applying +12V at the common terminal of relay. Remaining relays of the interface circuit board could also be configured with the microcontroller in the similar fashion
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